.tanchang{
       position: fixed;
       top: 0;
       left: 0;
       background: rgba(0,0,0,0.5);
       .center4{
           position: absolute;
            top: 50%;
           left: 5%;
           background: #FFFFFF;
           transform:translateY(-50%);
            -ms-transform:translateY(-50%);     /* IE 9 */
            -moz-transform:translateY(-50%);    /* Firefox */
            -webkit-transform:translateY(-50%); /* Safari 和 Chrome */
            -o-transform:translateY(-50%); 
           .headimg{
               width: 8rem;
               position: absolute;
               top: -4rem;
               left:50%;
               margin-left: -4rem;
           }
           .headimgbg{
               width: 12rem;
               position: absolute;
               top: -4rem;
               left:50%;
               margin-left: -6rem;
           }
           .top{
               height: 4px;
               background: url(../../img/pinggu_sq/111.png) no-repeat;
               background-size:100% 100%;
           }
           .jianjie{
               padding-top: 5rem;
               span{
                   color: #2571c5;
               }
               
           }
           .but{
                  position: absolute;
                  bottom: 1rem;
                  left: 10%;
                   background: #6eb3ff;
               }
       }
       .center4{
           li{
               img{height: 3rem;}
           }
           .neirong{
               background: #f4f9ff;
               padding: 5%;
               border: solid 1px #e4edf9;
               margin-bottom: 7.2rem;
               textarea{
                   border: none;
                   background: none;
               }
           }
          }
   }